I understand that, in the latest version of Pak64, the keys for the sliced underground mode increasing and decreasing of levels are ( and ) respectively. Might I suggest that these be swapped with the keys for increasing and decreasing the brightness, being + and - respectively?

Changing levels in underground mode is likely to be an operation that users need to perform regularly, and, as such, having the relatively unintuitive ( and ) keys is not very helpful. Worse than that, the ( and ) require SHIFT to be applied, making it very awkward to use regularly.

Conversely, players rarely want to change the lighting level manually. Indeed, some find it confusing that the lighting level changes when the press the + or - keys. It would make it much easier for players to understand what is happening if the + and - keys were used for the sliced underground mode, and leave the ( and ) keys for changing the lighting level.

The + and - keys are historically. They could be swapped for () indeed. However, with many laptops they lack direct acess to HOME/END, and those keys are not present even on some (albeit mostly obsolete) unix workstations (as opposed to ()).